Title: Zooplankton species and stages from the Barents Sea MIZ, and Amundsen and Nansen Basins
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Principal Investigators |
Project goals
Extensive sampling and analysis of zooplankton has been carried out in the Barents Sea Marginal Ice Zone (MIZ) and Amundsen and Nansen Basins. This project seeks to make the resulting data available to the ArcOD database.
Results
Totally, 97 net samples and 130 water bottle samples collected during three cruises in the Barents Sea were sorted. In total, 39 species and 80 categories (including developmental stages) were distinguished, counted and measured. Seasonal and regional variations in biomass and vertical distribution of mesozooplankton as well as cohort development in Calanus spp. were investigated along transects across the central Barents Sea and marginal ice zone during three cruises. Whereas there were appreciable biomass variations on a regional scale, the seasonal difference in biomass was insignificant. Throughout the investigation, the average biomass for the entire region approximated to ca. 5 g DW m-2 while station-to-station variations ranged in an order of magnitude (1-14 g DW m-2). Biomass of nauplii and small copepods (<500 μm in body length) obtained from water-bottle samples exceeded that from WP-2 net samples by a factor of 1.5-6.6. The maximum nauplii abundance reached 14*105 ind m-2 in the upper 100-m layer. A comparison of spatial distribution and cohort progress in C. finmarchicus and C. glacialis revealed two cores of spring events: the first started in the southernmost location of the Barents Sea, the second – nearby the Polar Front, and both developed towards the north. The variations in zooplankton community structure were influenced by both hydrographic conditions and bottom topography. Species composition in the Atlantic and the Arctic waters differed significantly with Calanus finmarchicus inhabiting Atlantic water and Calanus glacialis Arctic water.
